1. Field of the Invention
This invention relates generally to minimizing the suspension resonance and air-bearing resonance of data transducing heads, and to minimizing the head-to-disk contact and wear, and, more particularly, to a device and apparatus for minimizing the suspension resonance and air-bearing resonance of data transducing heads and for minimizing the head-to-disk contact and wear during contact start-stop processes with laser-textured magnetic recording media.
2. Description of the Related Art
Magnetic disks and disk drives, with their associated data transducing heads, are well known for their utility in storing data and information in magnetizable media. Typically, for hard disk drives, one or more rigid disks, having magnetizable media disposed thereon, are rotated at high speeds about their symmetry axes while data transducing heads are positioned as close as possible to the reading and recording surfaces, i.e., at minimized "flying heights." The data transducing heads, typically deposited on the trailing edge of a slider, are maintained at controllable distances from the reading and recording surfaces, during reading and recording operations, with the sliders (and the data transducing heads deposited thereon) floating on "air-bearings" as the disks rotate. The data transducing heads generally contact their associated reading and recording surfaces only when the disks are not rotating, during acceleration just after the disks start to rotate and during deceleration just before the disks stop rotating. The need to minimize flying height in order to increase data storage density is conditioned by the need to avoid excessive static friction ("stiction") and dynamic friction during contact start-stop processes such as the starting and stopping of disk rotation.
One traditional way of minimizing flying height is to make the reading and recording surfaces, as well as the data transducing head surface, as smooth as possible. However, such surface smoothness may lead to excessive stiction and friction during contact start-stop processes.
In U.S. Pat. Nos. 5,062,021 and 5,108,781 to Ranjan et al., the recording surfaces of magnetic disks are described as being intentionally roughened to reduce head/disk rest stiction. For example, laser-texturing has been used wherein the magnetic disk is rotated at a controlled rate corresponding to the firing frequency of a pulsed laser, forming a spiral of crater-like depressions and rims in the magnetic disk surface with repeated turns of the spiral combining to form an annular band. Laser-texturing of the surfaces of magnetic disks has provided a high degree of control previously unattainable with grit cloth or paper texturing. The accuracy of the laser enables the precise delineation of the laser-textured area boundaries. The laser power, pulse length and focusing have been made variable to control the size and profile of the laser spots or marks. The pulse frequency, in conjunction with the rotation or other relative translation of the magnetic disk have also been controlled to determine the spacing among adjacent marks.
A major disadvantage of conventional laser-texturing of magnetic disks is that the laser-textured magnetic disks are typically patterned with a well-defined periodicity of spot height, shape and separation. This well-defined periodicity in spot height, shape and separation can easily resonate the suspension and air-bearing of the data transducing head. These resonances, in turn, can greatly increase the head/disk contact forces, leading to a deterioration in tribological performance.
The present invention is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.